This disclosure relates to the formation of fabric preforms for composite components. In particular, this application relates to manipulation of a fabric to improve fabric preform quality.
Composite components are often used in applications in which having a high strength-to-weight ratio is important such as, for example, aircraft components. Many structural composite components can be made by wrapping a high-strength fabric around a form to create what is known as a fabric preform, applying a resin to the fabric preform, and then curing the resin to form the final composite component.
Certain features, however, are problematic to form. For example, in a fan containment case with one or more end flanges, the end flanges typically must be separately formed from the remainder of the cylindrical body. Because fan containment cases are often made with a tri-axial fabric (hoop tows in a first direction and bias tows in two other directions) to increase strength, it is not trivial to form the end flanges with the same piece of fabric used to form the cylindrical or near-cylindrical body.
Traditional methods of forming an end flange are (1) including recurring linear darts in each ply, (2) eliminating hoop tows and allowing the bias tows to shear, and (3) adding a separate flange detail. However, all of these approaches add cost and weight since they generally require more material to reinforce the flange.
Hence, a need exists for improved ways to form fabric preforms with features that require high amounts of fabric shear without significantly compromising the structural integrity of the resultant component.